Background and Objectives. Sequential treatment with the addition of high-dose therapy (HDT) and peripheral blood progenitor cell (PBPC) rescue has been reported to be active as front-line therapy in aggressive non-Hodgkin's lymphoma (NHL) with bone marrow (BM) involvement. We designed an intensive sequential therapy as front-line therapy in this subset of patients and conducted a phase II study. Design and Methods. Patients with aggressive non-Hodgkin's lymphoma and BM involvement at diagnosis received 8 weeks of VACOP-B chemotherapy as Induction therapy. The second phase included high-dose cyclophosphamide (HDCY) (7 g/m(2)) with granulocyte colony-stimulating factor (G-CSF) followed by leukaphereses. The third phase included HDT according to the BEAM protocol or melphalan (140 mg/m(2)) plus total body irradiation (8 Gy in a single dose). Results. Forty patients were Included in the study. According to the intention-to-treat, after VACOP-B, 11 (27.5%) and 22 (55%) patients achieved complete remission (CR) and partial remission (PR), respectively. Thirty-four received HDCY. After HDCY, 18 patients (45%) were in CR and 13 (32.5%) in PR. Twenty-nine underwent HDT plus peripheral blood cell rescue (PBPC) rescue. At the completion of treatment 29 patients (72.5%) were in CR, and 3 patients (7.5%) in PR. The actuarial 3-year overall survival, disease free survival and failure free sur vival are 48%, 55% and 40%, respectively. Overall severe toxicity was 7.5%. Interpretation and Conclusions. This phase tl study suggests that the intensified treatment described is feasible and active in aggressive NHL with BM involvement. A randomized trial is now underway to test this approach. (C)2000, Ferrata Storti Foundation.852160166